Effects of an angiotensin-converting enzyme inhibitor on residual renal function in patients receiving peritoneal dialysis. A randomized, controlled study

Abstract

Background: Residual renal function is an important determinant of mortality and morbidity in patients receiving peritoneal dialysis. However, few studies have evaluated therapeutic approaches for preserving residual renal function after the initiation of dialysis.

Objective: To test the hypothesis that the angiotensin-converting enzyme (ACE) inhibitor ramipril slows the decline in residual renal function in patients with end-stage renal failure treated with peritoneal dialysis.

Design: Randomized, open-label, controlled trial.

Setting: Single-center study in the dialysis unit of a university teaching hospital.

Patients: 60 patients receiving peritoneal dialysis.

Measurements: Patients were randomly assigned to ramipril (5 mg daily) or no treatment. The target blood pressure was 135/85 mm Hg or less. Rate of decline in residual glomerular filtration rate (GFR) and development of complete anuria were compared among groups.

Results: Over 12 months, average residual GFR declined by 2.07 mL/min per 1.73 m2 in the ramipril group versus 3.00 mL/min per 1.73 m2 in the control group (P = 0.03). The difference between the average changes in residual GFR in the ramipril and control groups from baseline to 12 months was 0.93 mL/min per 1.73 m2 (95% CI, 0.09 to 1.78 mL/min per 1.73 m2). At 12 months, 14 patients in the ramipril group and 22 in the control group developed anuria. With intention-to-treat multivariable analysis using the Cox model, it was estimated that at 3, 6, and 9 months, patients assigned to ramipril had a higher adjusted hazard of complete anuria than did patients assigned to no treatment. Of the 25 patients who still did not have complete anuria at 12 months, those assigned to ramipril had a better prognosis than did those assigned to no treatment (adjusted hazard ratio, 0.58 [CI, 0.36 to 0.94]). The rates of death from any cause, duration of hospitalization, and cardiovascular events did not differ significantly between groups.

Conclusions: Although the trial was small and had a limited ability to exclude effects of potential confounding factors, the angiotensin-converting enzyme inhibitor ramipril may reduce the rate of decline of residual renal function in patients with end-stage renal failure treated with peritoneal dialysis.